1. Field of the Invention
The invention comprises a revolving door comprising an at least partly cylindrical shell wall, including an entrance and an exit, and including two rotating door leaves which during normal operation are fully and oppositely extended inside the shell wall. Between the shell wall and an end of at least one door leaf, which end can move near and along the shell wall, a sliding door is provided, which is suitable for closing off either the entrance or exit, and during normal operation the end of the door leaf is constantly positioned near the sliding door and between its lateral edges.
2. Description of Related Art
Applicants have already been marketing such a revolving door for some considerable time. Since there is no barrier of any kind between the entrance and exit when the door leaves are in a particular position there is a problem of draught, unless further measures are taken. In order to avoid this draught problem, two such revolving doors are sometimes employed in practice, so that there is always one set of door leaves to form a barrier to an unhindered passage from the entrance of the first revolving door to the exit of the second revolving door. Such an embodiment involving a double revolving door is known from the European patent EP-B-0 663 981 in the name of applicants.
From DE-U-9420531 a revolving door is known embodied with an at least partly cylindrical shell wall, which is provided with an entrance and an exit and two rotating door leaves, which during normal operation are placed in each other's extended direction inside the shell wall, and whose ends open out into display cases. Between the shell wall and each display case at the end of the door leaf there is a sliding door. The rotation of the door leaves creates an open communication between the entrance and the exit of the prior art revolving door, giving rise to draught problems.
One object of the invention is the elimination of the draught problem of such an isolated, single revolving door.
To this end, the revolving door according to the invention is characterized in that the sliding door is independently suitable for closing off the entrance or exit, respectively, and in that during normal operation—at least during the passage of the door leaf—the end of the door leaf is constantly positioned near the sliding door and between its lateral edges. In this way the sliding door is able to provide a closure between the entrance and the exit, while the door leaves pass the entrance and exit to maintain the traffic of persons between entrance and exit of the revolving door.
In this way various revolving door embodiments are feasible. For example, the sliding door may be placed in a permanent rest position near the entrance or exit to allow the same to be closed off during the passage of a door leaf and to subsequently return to said rest position.